Deep water oil well drilling system



Feb. 26, 1952 T. M. Kuss ETIAL 2,586,966

DEEP WATER OIL WELL DRILLING SYSTEM 4 Sheets-Sheet l Filed Aug. 8, 1949 AYE a .4 AYAVAYA. 5

I INVENTOR. THEODORE M. K0551.

RALPH o. RUSSELL. BY

F -Z 1952 T. M. Kuss ETAL 2,586,966

DEEP WATER OIL WELL DRILLING SYSTEM Filed Aug. 8, 1949 4 Sheets-Sheet 2 INVENTOR. THEODORE IW- K055 RALPH o. eusszsu. BY

'ATTOQ yEYS,

Feb 26, 1952 T. M. KUSS EI'AL DEEP WATER OIL WELL DRILLING SYSLIEM Filed Aug. 8; 1949 4 Sheets-Sheet 3 INVENTOR. THEODORE M. (USS.

RALPH D. RUSSELL BY ATTORNEYS Feb. 26, 1952 uss ET AL 2,586,966

DEEP WATER OIL WELL DRILLING SYSTEM Filed Aug. 8, 1949 4Sh'e efcsSheet 4 INVENTOR. THEODORE M. I uss RAI PH 0. RUSSELL Patented Feb. 26, 1952 2,586,966 DEEP WATER 01L WELL DRILLING SYSTEM Theodore M. Kuss,

San Francisco, and Ralph Denton Russell, Oakland, Calif. Application August 8, 1949, Serial N 0. 109,212

i 19 Claims.

This invention relates to a structure which may be employed to remove oil from the soil under the ocean bed and which structure has certain similarites to that disclosed in our copending application, Serial No. 55,044 filed October 18, 1948.

One of the objects of this invention is the provision of a structure for oil drilling at sea which may be partially constructed on land and thereafter towed to the site at which drilling operations are to take place so that the work of assembly involved at the drilling site is a minimum.

Another object of the invention is. the provision of a structure of such a shape that it may be built economically and still have the required strength to resist stresses due to floating the same on water and those due to erection of the structure under water. Still another object of the invention is the provision of a structure for oil drilling at sea which permits the floating of such structure out to sea without creating excessive drafts.

And yet another object of the invention is the provision of means for adequately anchoring such an oil drilling structure at sea so that the same may resist natural forces of wind, waves and earthquake without undue movement.

Other objects and advantages will be apparent from the specification and the drawings wherein: Fig. l is a schematic side elevational view of the caisson structure partially completed on a building ways.

Fig. 2 is a schematic end elevational view of the structure shown in Fig. 1.

Fig. 3 is a schematic side elevational view of the caisson portion of the structure being floated to the oil drilling site.

Fig. 4 is a schematic end elevational view of the Water borne structure shown in Fig. 3.

;Fig. 5 is a schematic side elevational view of the caisson of Fig. 3 when the same is partially up-ended by admission of water into two of the tubular legs. .1

Fig. 6 is a schematic side elevational view of the caisson of Fig. 3 after the same has been brought to a vertical position by admission of water into the legs.

"Fig. '7 is a schematic side elevational view of the caisson of Fig. 6 resting on the ocean bed. Fig. 8 is a schematic side elevational view of the completed structure including decks employed for supporting the derrick andother well drilling structure.

Fig. 9 is a side elevational view of the structure preparatory to towing the structure to another site.

Fig. 10 is a cross-sectional view through the caisson showing the position of the spud tubes in the caisson legs when the structure is eme ployed on a relatively hard ocean bed.

Fig. 11 is a schematic cross-sectional view of. one leg of the caisson showing the watertight partitions and means for flooding the watertight cells within the legs. Fig. 12 is an enlarged elevational view of one leg only of the caisson showing the means employedfor anchoring the same on a relatively soft ocean bed.

Fig. 13 is an enlarged elevational view of one leg only of the structure showing the means employed for anchoring the same on a relatively hard ocean bed, I i

Fig. 14 is a greatly enlarged cross-sectional view through a portion of the leg shown in Fig. 13 illustrating the means for leveling the struc-' ture when the ocean bed is irregular.

Fig. 15 is a greatly enlarged transverse crosssectional view through one leg of the structure as taken along lines l5.|5 of Fig. 12.

Fig. 16 is a greatly enlarged side elevational view partly broken away and in section of the base portion of the legshown in Fig. 12.

Fig. 17 is a fragmentary cross-sectional view of a portion of the leg of Fig. 12 showing the means employed for guiding the pile driver.

Fig. 18 is a fragmentary cross-sectional view of a portion of the leg of Fig. 12 showing the means employed for guiding the piling.

Fig. 19 is an enlarged cross-sectional view through the spud and spud guideas taken along lines I9 |9 of Fig. 14.

The invention comprises a generally elongated caisson having three legs which are adapted to extend between the bed and the surface of the ocean or other body of water. These legs are generally designated at I, 2 and 3 in the drawings and are preferably fabricated of steel and made watertight. Upon installation of the caisson with the legs I, 2 and 3 disposed vertically and with theirlower ends on the bed of the ocean a deck or superstructure generally designated 4 (Fig. 8) may be erected on theupper ends of the legs I 2 and 3 by any approved manner such as welding or riveting. Thisdecli 4 is of such form and strength as to support an oil drilling derrick 5 (Fig. 8) and other oil drilling equipment such as engines, fresh water tanks, compressors, generators which are required in conventional oil drilling installations. The legs I, 2 and 3 are hollow and cylindrical and are identical in all respects. These legs may be integrally secured together by bracing and frames generally designated 6 in the drawings. It is preferable that the caisson be generally triangular in cross-section (Figs. 4 and 10) with one of the legs positioned at each apex of the triangle. This shape is an important feature of the invention for reasons which will be described subsequently. in greater detaiL- Referring to Figs. 1 and 2 it is seen that the caisson may be fabricated on a building ways such as that from which ships 'are normally launched. Legs 2 and 3 may be disposed in a horizontal plane and integrally connected-by suitable bracing 6 as shown in Fig.2. and then the leg I may be erected upon similar bracing (Fig. 4) in any approved manner. Upon launching the caisson the buoyancy of the hollow legs 2, 3 will be sufficient to support the leg I and most of the caisson .structure out .of .thewater. The method of closing th'e...en'ds"oi the. legsto provide a watertight structurewill be explained subsequently in detail. It yvi1l be noted that the caisson'when waterborne is an exceedingly stable structure and jone which, may be'readily towed f to the drilling site withoutpossibility of capsizing. Referring to"Fig." 11 wherein certain ballast control mean'sare shown schematically in. one l'egLZfof the caissonfit' isseen th'at. each of ,the tubular legs I, land 3 is providedwith-a trans.- verse watertight bulkhead] ll at'the lower. end o f the leg, This bulkhead Illis preferably larger in diameter than'the leg. to .provide an annular flange 'I3 around the periphery o ffthe leg ad-v jacent itslowerend.

jflntermediatejthe ends}. oi. the .1egs I', 2 and V 3, bu preferably'jsomewhatcloser to the bottom than the top, is'a transverse watertight bulkhead I I which creates a. watertight .coinpartmeritmr el d ac t the. lower enact. ea h lea,

1 Adjac n th ..1 pn rend. of. each .o fl the legs' 2 and 3 'is a;watertight' bullshead1I2]which is isr ly. s c d "from the; pper end f. h tubular leg to provide a' working space.,g.,for operators. "This bulkhead. I2 and thein'terrnee diatebulkhead I l define a watertightbompart mefnt or cell B (Fig. 11) i "A flooding valve Iisiprovidedladjacent the lower end of cell A to admit water into thecell'A upon operation of control rod 59 from the top of the caisson; To permit escapejoi 'airffrom cell A a relief valve I6 is provided adjacent jtli e upper end of the cellwhich may'bereiriotely controlled by control rod 20." t

In a similar manner, c'ellB 'is"provide'd with flooding and vent valves" I1 and I 8 respectively which in turn may be operated by controlrods 2I and 22 from the top of the caisson.

It. will be apparent .from..Figs. 3-6. that the caisson may be swung from its horizontal floating positionof Figs. 3 and .4 to the position of Fig. 5 by theopcningofvalves I 5 and I5in1 egs2 and 3. To-retain maximum possible control over the structure it is important thatv the above-valves irr legs 2.and 3 be opened concurrently so thatthe structure does not tend to tilt transversely of. its length during submergence. If the loss of; buoyancy due. to flooding cell A is notsufficient tolbringthe lower end-of leg I into the wateradditional selective flooding of cell B may be resorted .to by operation .of valves I1 and. I8.

il fthe valves Ifiand; I B of leg I- are open when It. will be apparent that a four-legged structure for example would not lend itself to accurate control during the above described operations because unstable conditions might be created which would not be visibly apparent during the submergence of the structure. If, for example, in afourlegged structure two diagonally opposite legs only were flooded when the caisson is in the position of Fig. 6, submergence might continue but the structure would be unstable and a; sudden swinging about a horizontal axis might ensue thereby setting up undesirable stresses in the caisson and .creatingdangerous. conditions. Upon continued flooding of. thecells-Bthe caisson maybe submerged .as slowly as desired until the caisson is supported at its lower end on the bottom. (In the event that the-ocean bed is irregular, additional means :will be required to levelthe structure and such means will be subsequently described).

As will be subsequently. described in detail, a substantial portion of the caisson is adapted to be removed after the. oil drilling operation-has been performed. The' portion which may beremoved contains thecells A, B and C and maybe thereafter employed at another site if. desired. Forraising the caisson air lines 23 and 24.may be employed for removing the water fromcells A and B. Air line 23 communicates between cell C and cell A and may extendto a compressor on a barge (not shown) or on the structure .itself I for the purpose of forcing thewater from .cell A pending on the characteristics of the ocean bed at the site. If the bed is level little difficulty is encounted. If thebed is irregular and relatively.

soft the caisson maybe leveled to a certainlextent by increasing the amount of water admitted.

I to the legs on the high side,- thus causingone or will now be described inconnection with two of the legs to sink further into the mud than. the leg or legs resting on the lower side. ,.If'. varying the amount of water ballast does not permit bringing thecaisson-toa vertical position.

additional levelling means are employed which method of anchoring the caisson.

Levelling and anchoring means for soft beds Figs. 12, l5 and 16 illustrate the. method em ployed for anchoring the caisson on a relatively soft ocean bed and at the same time insuring that the caisson will be disposed vertically before the deck and derrick construction is com- ;.menced. An annularrow of longitudinally extending angle bars 39 are rigidly secured to the. periphery of each of the tubular'legs I, Zand 3 (Fig..15). These angles 38 stiffen the legs and the also serve as guides for the piles and the pile driver employed to anchor the caisson on the ocean bed. The angles 30 are arranged in pairs with the free flanges of the angles of each pair directed away from each other as shown in Fig.

15. Referring to Fig. 1'7 it is seen that generally elongated yokes 3| are adapted to be slidably secured at its ends to a pair of the angles 3|] by a pair of spaced, opposedly opening channel.

members 32 each of which engages one angle of each pair. Rigidly secured to the yoke shown in Fig. 17 as by bolts 33 is a conventional underwater pile hammer generally designated 34 which serves to drive each of the piles 35 into the bed of the ocean.

Secured'to each pile at spaced points along the length of the same are yokes 36 which are similar to yokes 3 I, but which are spaced from the piles 35] i by means of brackets 31 so that the longitudinal centerline of the pile is in alignment with the line of action of the pile hammer.

The use of underwater pile driving hammers per se is not new and no claim is made to such use except in combination with the present invention.

The brackets 3'! may be lightly tack welded to the pile 35 (Fig. 18) so that upon engaging the flange I3 the brackets 31 will be brokenflojfi the piles by additional blows of the pile driveigf Of course, by the time the yokes 36 and their .36 associated brackets 31 have reached the flanges I3 these brackets hay-e substantially perfonnefd their function of guiding the pile since the pile has entered the bed of the ocean at its lower end. The spacing of yokes 36 is shown in Fig. 12 but it is obvious that the spacing shown in the drawings may be changed as desired so long as the pile is sufliciently stable to resist buckling. T I t will be noted from Fig. 12 that the lower end of the pile hammer 34 is sufficiently spaced from the lower yoke 3| so that the completely driven. pile will be below the flange I3. This is for the. purpose of permitting subsequent removal of the jacent the top of the casing which it is desiredv to raise. In Fig. 12 a pile 50 is shown employed in this manner. A conventional hydraulic jack 5| is secured at one of its ends to a strong back 52 which may be temporarily though rigidly se cured to the top of the casing- 3 as by welding.

Several yokes 36 may be secured to the pile 550 r at spaced points along its length to prevent buck-' ling of the pile during the jacking operation. By actuating the jack 5| the casing 3 maybe raised until the tops of the legs I, 2 and 3 are in the same horizontal plane. If required by'the irregularity of the ocean bed, the jacking operation above described may be carried out on two of the three casings to bring the caisson 1.0a vertical position. Thus it is seen that the use of the angles in combination with the pilesand the jacking pile provide an effective means for manipulating the caisson after been brought to its final position at the drilling site.

After the piles have been driven to deptlrat which their upper ends are adjacent the lower end of the caisson but projecting above the ocean bed, concrete may be poured around the base to anchor the caisson securely in place. Surrounding the lower end of each leg is an openended cylindrical chamber or skirt generally designated (Fig. 16) into which the concrete is poured so that the upper ends ofthe piles become imbedded in the concrete after the latter sets. The skirt 6|] is slidably secured to a circular shaped frame 6| which in turn is rigidly fastened to a base portion 62 secured to the lower of each of the legs I, 2 and 3. The base portion 62 is an open-ended cylindrical tube having an annular flange 63 rigidly secured to the upper end thereof and peripherally welded thereto. The outside diameter of flange 63 is preferably equal to the outside diameter of watertight bulkhead IB and this flange is brought into direct engagement with the flange I3 hereinbefore referred to as the portion of bulkhead I0 extending radially outwardlly of the side walls of each of the casings I, 2 and 3. These flanges may be secured in place relative to each other by bolts during fabrication but such bolts are replaced by straps 64 prior to launching. As seen in Fig. 16 angle clips 65, 66 are secured to the side walls of the watertight cell A and the base portion 62 respectively. adjacent their juncture. Straps 64 may then be welded to the clips 65 and 66 so that these straps securely connect the casingwith the base portion. As will be subsequently described, the straps 64 may be burned through by a diver if desired to release the caisson to move it to a new site.

Referring to Fig. 16, the frame 6| comprises a pair of circularly formed angle bars 10, 1| which are spaced longitudinally of the base 62 and secured together by members 72. Angie I0 is rigidly secured to the base portion 62 by means of diagonal braces 13 so that the angle bars 70, 1| which define the periphery of frame 6| are concentric with and spaced from the base portion 62.

The skirt 60 is slidably supported on the frame 3| so that it may be moved longitudinally of the leg. Angle bar 15 is rigidly secured around the inner periphery of the skirt 60 adjacent its upper open end and a similar angle bar 16 is similarly secured to the skirt adjacent its lower open end but preferably spaced therefrom as shown in Fig. 16.

. The angle bars 15 and 16 act as stops but permit limited longitudinal movement of the skirt 60 relative to the base portion 62.

, When initially launched the skirt 6!! may be positioned at its upper limit as shown by dash lines in Fig. 16 and held in place by means of cables 11 secured to lugs 78 on skirt 60 during floating and upending. Before the concrete is poured the cables 11 may be slackened thus permitting the skirt 60 to drop downwardly by gravity onto the ocean bed as indicated by full line in Fig. 16. The circular frame 6| acts as a guide during this movement of the skirt and prevents undesirable tilting of the skirt.

-. To insure a rigid connection between the piles 35 and the casings I, 2 and 3 openings 19 may be formed in the base portions 62 to permit the concrete to enter the same. These holes are preferably elongated in a vertical direction so that water trapped in the base portion 62 may escape as the level of the concrete rises during the pouring operation. The operation of pouring tremie or underwater concrete is not new in itself and no claim is made herein to such an operation except as the same is used in combination with the present invention. The tremie concrete which is indicated at 86 in Fig. 13 should be of suificient quantity, to insure an adeshow its relative position with respect to the leg and the skirt 69. This pile is indicated in dotdash line for clarity.

. Labelling and anchoring means for hard bed Figs. 19, 13 and 14 illustrate the method employed to anchor the caisson to a relatively hard ocean bed. In such a case the use of piles may be obviated and the method of anchoring the caisson becomes correspondingly simplified, it being only necessary to pour the concrete adjacent the base of each leg in the manner hereinbefore described.

However, means must be provided for levelling the caisson in the event that the ocean bed is irregular at the site. In lieu of the piles employed as above described for jacking the caisson .we employ an elongated column or spud generally designated 99 (Figs. 13, 14) which is adapted to be inserted into each of the legs I, 2 and 3 for movement longitudinally of the latter. For the purpose of guiding these spuds 99 a cylindrical guide tube 9| is formed in each of the legs I, 2 and 3 and extends throughout the length of cells A and B (Fig. 13) Communicating with the cylindrical guide tube 9| is another guide tube 92 rigidly secured within the base 52. Guide tube 92 is in alignment with guide tube 9| so that the spud 99 may extend into and through the base 62. The guide tube 92 is provided with a flange 93 adjacent its upper end for securing the tube to the watertight bulkhead I9. This flange 93 may be formed integrally with the flange 63 and if desired the flange 93 may be lightly tack welded to the lower watertight bulkhead I9. This flange 93 may be formed integrally with the flange 63 and if desired the flange 93 ma be lightly tack welded to the lower watertight bulkhead E9 of the caisson leg so that upon severing the straps 64 as hereinbefore described, the caisson may be completely released from the base 62 and also from the guide 92.

The cylindrical guide 92 is somewhat larger in diameter than the guide 9| and a sleeve generally designated 94 is adapted to be slidably received within said guide. This sleeve 94 is approximately equal in length to the height of base 62 and comprises an outer wall 95 slidable within guide 92 and an inner wall 96 within which the spud 99 is adapted. to be moved longitudinally of the caisson. The walls 95 and 99 are concentric and are radially spaced by longitudinally extending flat bars 91 rigidly secured to said walls (Fig. 19).

For the purpose of centering the spud 99 within the guide 9| and sleeve 94 circular spacers I99 are rigidly secured to the spud 99 at spaced points along its length (Fig. 14). The inside diameter of inner wall 98 is aproximately equal to the inside diameter of guide 9| so that the spud 99 may be inserted through the full vertical extent of the caisson leg.

The lower end of the spud 99 is provided with a circular base I9I rigidly secured to the leg and having a diameter approximately equal to the diameter of the spud spacers I99 so that said base may be inserted through the guide tube 9| and sleeve 94.

Rigidly secured to the lower end of sleeve 94-is a circular spud shoe I92 which is substantially larger in diameter than the base WI and which is adapted to bear against the ocean bed to partially support the weight of the caisson. This spud shoe I92 .is preferably formed of a relatively large circular plate I93, reinforced by stiffeners I94 and rigidly secured to the lower end of sleeve 94 by means of plate I95.

It should be noted that the spud 99 is not connected to spud shoe I92 although it coacts therewith. To permit even distribution of the force exerted between the spud base I9I and the spud shoe 192 we provide a sand cushion I99 at the lower end of sleeve 94. The sand I96 transmits the force from the spud base .I9I to thespud shoe I92 and prevents localized distortion of the spud base or spud shoe. It will be apparent that upon removal of the caisson from the drilling site, the sleeve 94 and spud shoe will remain but the spud may be withdrawn from the base 62 and removed along with the caisson. To prevent accidental removal of the sleeve during the sinking operation the same may be lightly tackwelded to the guide 92. Upon subsequent use of the spud 99 the sleeve will be broken loose.

Fig. 13 shows a general arrangement of leg 2 of the caisson for a hard bed installation. Strongback 52 and jack 5| may be employed in the same manner as they are employed in the soft bed installation shown in Fig. 12 except that the jack 5| is positioned within compartment C. It will be noted that legs I, 2 and'3, when arranged as shown in Fig. 13 for hard bed installations, may be formed with the longitudinal stifieners 39 secured to the inner periphery of the legs instead of to the outer periphery as shown in the soft bed installation of Fig. 12. This construction provides less resistance to the movement of water past the legs and is'possible because no pile driving operation need be per.- formed in the case of a hard bed installation.

To compensate for the piles 35 employed in a soft bed; it is preferable that the skirt for retaining the concrete be somewhat larger when no piling is used. The skirt I91 shown in Fig. 13 is therefore somewhat larger than skirt 69 of Fig. 12 but it will be understood that in other respects the installation of skirt I0! is identical to the installation of skirt 69.

For the purpose of carrying on the actual drilling operation from the deck 4- a plurality of oil drilling casings II9 (Figs. 1-6) may be rigidly secured to the bracing 6 in any convenient manner. These drilling casings may be open ended and are only for the purpose of guiding the drills pumping lines and associated tools during the actual drilling processes and preferably extend substantially the length of the caisson.

In the drawings the legs I,'2 and 3 have been shown parallel to each other but this particular shape is not essential although it is economical to make. If desired the legs I, 2 and 3 may slope inwardly and upwardly toward each other so that the base of the caisson when installed on the ocean bed is somewhat larger than the top of the caisson on which the deck is constructed. By this modification a more stable structure is achieved. However it is pertinent to note that the cross-sectional shape of the caisson should be triangular at any point along the length of the caisson with the legs I, 2 and 3 at the apex of each triangle for the reasons hereinbefore given. a

The invention herein disclosed has been described with respect to two different types of ocean beds. It will be apparent that the quality of the ocean bed encountered may actually be somewhere between hard and soft so that the particular structure employed may combine ele- 9 merits of both examples of the invention herein described.

It will be apparent that in relatively shallow water installations the piles may be driven at all times by a conventional pile hammer without requiring underwater pile driving and by welding additional sections of piles together a the pile driving operation progresses. In such a case the upper ends of the piles may be left projecting above the water level and the piles rigidly secured to the legs by welding the yokes 36 to both the piles and the legs. This type of installation may obviate the necessity of pouring concrete and permits withdrawal of the piles when it is desired to move the caisson to another site. However, in the relatively deep Water installations contemplated by the present invention the use of a concrete anchor as hereinbefore described is preferable.

I claim:

1. An oil-shore drilling structure comprising an elongated caisson adapted to be floated horizontally to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated integrally connected tubular legs for supporting an oil drilling deck thereon, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially air tight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while waterborne and for sinking said caisson for supporting the same on said bed. a

2. An off-shore drilling structure comprising an elongated caisson adapted to be floated horizontally to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated integrally connected tubular legs for supporting an oil drilling deck thereon, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially air tight cells, means for selectively admitting water into said'cells for swinging said caisson from a horizontal to a vertical position while waterborne and for sinking said caisson for supporting the same on said bed, means carried by each of said legs for tilting said caisson to a generally vertical position while said caisson is supported on said bed.

3. An oii-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated tubular legs for supporting an oil-drilling deck thereon, said caisson having a cross-section substantially in the form of a triangle with one of said legs at each apex thereof, longitudinally extending open ended casings secured to said caissons adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially watertight cells, mean for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is water-borne and for sinkin'g'said caisson for supporting the same on said bed, guide means integrally secured to each of said legs for slidably supporting an underwater pile driver for driving piles-longitudinally of said leg -and adjacent the periphery of the latter.

4. An off-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated tubular legs for supporting an oil-drilling deck thereon, said caisson having a cross-section substantially in the form of a triangle with one of said legs at each apex thereof, longitudinally extendmg open ended casings secured to said caissons adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said leg into substantially water-tight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, a chamber supported by each of said legs and surrounding the latter adjacent their lower ends for receiving a charge of concrete for connecting said legs to said bed.

5. An oil-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for upending onto the bed of the ocean with its upper end above the sea level and with its lower end on the ocean bed, said caisson comprising three spaced elongated integrally connected tubular legs for supporting an oil drilling deck thereon adjacent said upper ends, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into a plurality of watertight cells, said legs being provided with tubular base portions removably secured to said legs adjacent their lower ends for supporting said legs on said bed with said base portions between said legs and said bed, mean for rigidly securing said base portions to said bed whereby said legs may be released from said base portions for removing said caisson from said site.

6. An off-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for upending onto the bed of the ocean with its upper end above the sea level and with its lower end on the ocean bed, said caisson comprising three spaced elongated integrally connected tubu-. lar legs for supporting an oil drilling deck thereon adjacent said upper ends, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to' 7 said bed, transverse partitions in said legs dividing said legs into a plurality of watertight cells, said legs being provided with tubular base portions adjacent their lower ends for supporting said legs on said bed with said base portions between said legs and said bed, a chamber carried by each of said base portions and surrounding the latter and adapted to be supported on said bed for receiving a charge of concrete, openings in the sides of said base portions communicating with said chamber for permitting said concrete to enter said base portions.

7. An off-shore drilling structure comprising a vertical caisson supported at its lower end on the bed of the sea with its upper end above sea level, said vertical caisson comprising spaced elongated integrally connected tubular legs extending substantially the length of said caisson, transverse partitions in said legs at spaced points along the length of the latter dividing said legs into substantially watertight cells, tubular base portions secured to the lower ends of said legs and coaxial therewith for supporting said legs with their lower ends spaced from said bed, stiffeners extending longitudinally of said legs and rigidly secured thereto for slidably supporting an underwater pile hammer for movement longitudinally of said legs, said stiiieners being arranged in an annular row extending circumferentially of said legs for supporting such a pile driver at spaced points around the periphery of said legs and for driving piles arranged in an annular row concentric with said legs and radially spaced therefrom, an open ended cylindrical chamber carried by each of said base portions and adapted to be supported on said bed radially outwardly of said row of piles, said chamber being adapted to receive a charge of concrete for rigidly securing said piles to said base portion.

I 8. An off-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated tubular legs for supporting an oil-drilling deck thereon, said caisson having a cross-section substantially in the form of a triangle with one of said legs at each apex thereof, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially watertight cells. means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legs and adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction away from said bed for levelling said deck.

9. An oil-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated tubular legs for supporting an oil-drilling deck thereon, said caisson having a cross-section substantially in the form of a triangle with one of said legs at each apex thereof, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially watertight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legs and adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction'away from said bed for levelling said deck, interengaging. elements on said one leg and said jacking element for supporting the latter against buckling during said movement, said elements comprising longitudinally extending stiffeners onsaid legs and yokescarried by said jacking elements at spaced, points along their lengths 12 slidably secured to said stiffeners for movement longitudinally of said legs.

10. An oil-shore drilling structure comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean, said caisson comprising three spaced elongated tubular legs for supporting an oil-drilling deck thereon, said caisson having a cross-section-substantial-ly in the form of a triangle with one of said legs at each apex thereof, longitudinally extending open ended casings secured to said caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing said legs into substantially watertight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legsand adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction away from said bed for levelling said deck, means carried by said legs for supporting said jacking members against buckling,- said means comprising a guide casing within said legsextending longitudinally between the upper and lower ends of said legs and guide elements secured to said jacking element at spaced points along the length of the latter for slidably engaging said casing.

11. An ofi-shore drilling strusture comprising an elongated three sided caisson adapted to be floated horizontally on one side to a desired site for up-ending onto the bed of the ocean with its upper end above the sea level and with its lower end on the ocean bed, said caisson comprising three spaced elongated integrally connected tubular legs for supporting an oil drilling deck thereon adjacent said upper end, longitudinally extending open ended casings secured to said. caisson adapted to pass drilling and pumping lines to said bed, transverse partitions in said legs dividing them into a plurality of watertight cells, said legs being provided with tubular base portions adjacent their lower ends for supporting said legs on said bed with said base portions between said legs and said bed, levelling means carried by each of said legs and said base-portions, for swinging said caisson to a vertical position when said bed is irregular, said means comprising an elongated jacking member within said legs extending between the upper and lower ends of the lower ends of the latter and extending into said base portionsand a. bed engaging element carried by said base portion and slidably therein, jacking means carried bysaid legs adjacent their upper ends for urging said jacking member downwardly against said bed for selectively raising said legs off said bed.

12. In 'an off-shore drilling structure having three equally spaced air tight hollow legs connected together for floating said structure with two of said legs horizontal in the water and with the third leg above the water level, means for selectively and progressively displacing the air in one of the corresponding ends of said legs whereby said legs may be up-ended in the water and stabilized during such movement against rolling about a longitudinal axis common to-said legs.

13. In an oiT-shore drilling structure having three equally spaced air tight hollow legs connected together for floating said structure with two of said legs horizontal in the water and with the third leg above the water level, means for selectively and progressively displacing the air in one of the corresponding ends of said legs whereby said legs may be up-ended in the water and stabilized during such movement against rolling about a longitudinal axis common to said legs and means carried by said legs for supporting them on the bed of the ocean substantially normal to the water level irrespective or irregularities in the surface of said bed.

14. In an oiT-shore drilling structure having three equally spaced air tight hollow legs connected together for floating said structure With two of said legs horizontal in the water and with the third leg above the water level, means for selectively and progressively displacing the air in one of the corresponding ends of said legs whereby said legs may be up-ended in the water and stabilized during such movement against rolling about a longitudinal axis common to said legs, and a levelling member carried by at least one of said legs movable longitudinally thereof anp downwardly when said legs are up-ended witl said corresponding ends down.

15. In an off-shore drilling structure having equally spaced vertically extending legs in side by side relationship for supporting well drilling equipment, piles extending longitudinally of said legs connected therewith for downward movement and means on said legs for driving said piles downwardly, a skirt around the lower end of each of said legs and secured thereto through which said piles are adapted to move upon being driven downwardly, said skirt being adapted to hold concrete with a portion of each of said piles imbedded therein for thereby securing said piles to said legs.

16. In an off-shore drilling structure having equally spaced vertically extending legs in side by side relationship for supporting well drilling equipment, piles extending longitudinally of said legs connected therewith for downward movement and means on said legs for driving said piles downwardly, elongated members secured to said legs extending longitudinally thereof and means for slidably connecting said piles and said.

means to said members.

17. An oiT-shore drilling structure comprising a vertical caisson supported at its lower end on the bed of the sea with its upper end above sea level, said caisson comprising spaced elongated integrally connected tubular legs extending substantially the length of said caisson, transverse partitions in said legs dividing said legs into substantially watertight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legs and adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction away from said bed for levelling said deck.

18. An ofi-shore drilling structure comprising a vertical caisson supported at its lower end on the bed of the sea with its upper end above sea level, said caisson comprising spaced elongated integrally connected tubular legs extending substantially the length of said caisson, transverse partitions in said legs dividing said legs into substantially watertight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legs and adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction away from said bed for levelling said deck, interengaging elements on said one leg and said jacking element for supporting the latter against buckling during said movement, said elements comprising longitudinally extending stiffeners on said legs and yokes carried by said jacking elements at spaced points along their lengths slidably secured to said stifieners for movement longitudinally of said legs.

19. An off-shore drilling structure comprising a vertical caisson supported at its lower end on the bed of the sea with its upper end above sea level, said caisson comprising spaced elongated integrally connected t'ubular legs extending substantially the length of said caisson, transverse partitions in said legs dividing said legs into substantially watertight cells, means for selectively admitting water into said cells for swinging said caisson from a horizontal to a vertical position while the same is waterborne and for sinking said caisson for supporting the same on said bed, an elongated jacking member extending between the upper and lower ends of each of said legs and adapted to engage said bed at its lower end, jacking means adjacent the upper end of one of said elements for urging the latter toward said bed and for moving said one leg in a direction away from said bed for levelling said deck, means carried by said legs for supporting said jacking members against buckling, said means comprising a guide casing Within said legs extending longitudinally between the upper and lower ends of said legs and guide elements secured to said jacking element at spaced points along the length of the latter for slidably engaging said casing.

THEODORE M. KUSS. RALPH DENTON RUSSELL.

REFERENCES CITED The following references are of record in the file of this patent:

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